What are the statements in javascript?
JavaScript StatementsIn HTML, JavaScript statements are "instructions" to be "executed" by the web browser. Show
This statement tells the browser to write "Hello Dolly." inside an HTML element with id="demo": Exampledocument.getElementById("demo").innerHTML = "Hello Dolly."; Try it Yourself » For a tutorial about Statements, read our JavaScript Statements Tutorial. JavaScript Statement IdentifiersJavaScript statements often start with a statement identifier to identify the JavaScript action to be performed. Statement identifiers are reserved words and cannot be used as variable names (or any other things). The following table lists all JavaScript statement identifiers:
JavaScript applications consist of statements with an appropriate syntax. A single statement may span multiple lines. Multiple statements may occur on a single line if each statement is separated by a semicolon. This isn't a keyword, but a group of keywords. For an alphabetical listing see the sidebar on the left. Specifies the value to be returned by a function. Terminates the current loop, switch, or label statement and transfers program
control to the statement following the terminated statement. Terminates execution of the statements in the current iteration of the current or labeled loop, and continues execution of the loop with the next iteration. throw Throws a user-defined exception. if...else Executes a statement if a specified condition is true. If the condition is false, another statement can be executed. switch Evaluates an expression, matching the expression's value to a case clause, and executes statements associated with that case. try...catch Marks a block of statements to try, and specifies a response, should an exception be thrown. Declaring variables
Declares a variable, optionally initializing it to a value. let Declares a block scope local variable, optionally initializing it to a value. const Declares a read-only named constant. Functions and classes
Declares a function with the specified parameters. function* Generator Functions enable writing iterators more easily. async function
Declares an async function with the specified parameters. async function* Asynchronous Generator Functions enable writing async iterators more easily. class Declares a class. Iterations
Creates a loop that executes a specified statement until the test condition evaluates to false. The condition is evaluated after executing the statement, resulting in the specified statement executing at least once. for
Creates a loop that consists of three optional expressions, enclosed in parentheses and separated by semicolons, followed by a statement executed in the loop. for...in Iterates over the enumerable properties of an object, in arbitrary order. For each distinct property, statements can be executed. for...of Iterates over iterable objects (including arrays, array-like objects, iterators and generators), invoking a custom iteration hook with statements to be executed for the value of each distinct property. for await...of Iterates over async iterable objects, array-like objects, iterators and generators, invoking a custom iteration hook with statements to be executed for the value of each distinct property. while Creates a loop that executes a specified statement as long as the test condition evaluates to true. The condition is evaluated before executing the statement. OthersEmpty An empty statement is used to provide no statement, although the JavaScript syntax would expect one. BlockA block statement is used to group zero or more statements. The block is delimited by a pair of curly brackets. debugger Invokes any available debugging functionality. If no debugging functionality is available, this statement has no effect. export Used to export functions to make them available for imports in external modules, and other scripts. import Used to import functions exported from an external module, another script. labelProvides a statement with an identifier that you can refer to using a with Extends the scope chain for a statement. Difference between statements and declarationsIn this section, we will be mixing two kinds of constructs: statements and declarations. They are two disjoint sets of grammars. The following are declarations:
Everything else in the list above is a statement. The terms "statement" and "declaration" have a precise meaning in the formal syntax of JavaScript that affects where they may be placed in code. For example, in most
control-flow structures, the body only accepts statements — such as the two arms of an
If you use a declaration instead of a statement, it would be a
On the other hand,
You can see
declarations as "binding identifiers to values", and statements as "carrying out actions". The fact that As another example, labels can only be attached to statements.
To get around this, you can wrap the declaration in braces — this makes it part of a block statement.
Browser compatibilityBCD tables only load in the browser See alsoWhat are the types of statements in JavaScript?Contents. Summary.. Block Statement.. Conditional Statements. if… else Statement. switch Statement.. Loop Statements. for Statement. do… while Statement. while Statement. ... . Object Manipulation Statements. for… in Statement. for each… in Statement.. Comments.. Exception Handling Statements. Exception Types. throw Statement. try… catch Statement.. What is JavaScript statement example?JavaScript statements are the commands to tell the browser to what action to perform. Statements are separated by semicolon (;). JavaScript statement constitutes the JavaScript code which is translated by the browser line by line.
What are the three types of statements in JavaScript?Conditional Statements. If..else statement. • The if statement is used to execute a block of code if the given condition evaluates to true. ... . Switch Statement. • Switch statement gives us the flexibility to execute different statements based on different values of the expression.. What's a statement in JavaScript?JavaScript statements are used to control the flow of a script or a program. The statements are composed of values, expressions, operators, comments, and keywords. Ideally, any JavaScript code you write is made up of separate statements.
|